It is very common at present that specific persons necessarily use or require for their work, the use of a personal computer, of a mobile telephone and, of course, of a watch, the three elements of which are uncomfortable to carry continuously, especially since they form independent bodies.
In such circumstances, there are specific moments and places when the function or use of one of those elements is necessary, being sometimes impossible, since the user may have left the personal computer or even the mobile telephone in, for example, his own car or in the office, when he is meeting another person or is in a specific place, other than his car or his office.